A Simple Organocatalytic Enantioselective Cyclopropanation of α,β-Unsaturated Aldehydes

Abstract A highly chemo‐ and enantioselective organocatalytic cyclopropanation of α,β‐unsaturated aldehydes with bromomalonate and 2‐bromoacetoacetate esters is presented. The reaction is catalyzed by chiral amines and gives access to 2‐formylcyclopropanes in high yields and up to 99 % ee .